Add trendlines to all series in a chart with Toggle Button

[RaydenUK]

I am not having any luck with adding toggling trendlines on or off. Ideally, when the toggle is selected, trendlines would be added and once unselected they would disappear. My chart is modified with slicers, which can cause the trendlines to disappear, therefore, the code would have to recognize if trendlines are or aren't present and not throw an error or double up on the lines. I have several series in my chart and would need the trendlines to be formatted the same color as the respective series lines. Any help would be greatly appreciated. Thank you.

 

[mole999]

best way of avoiding duplication is to delete them all first and then reapply

I use this to produce a polynomial line

ActiveChart.SeriesCollection(2).Trendlines(1).Select
With Selection.Format.Line
        .Visible = msoTrue
        .Weight = 2
        .ForeColor.ObjectThemeColor = msoThemeColorAccent3
        .ForeColor.TintAndShade = 0
        .ForeColor.Brightness = 0
        .Transparency = 0
        .BeginArrowheadStyle = msoArrowheadDiamond
        .EndArrowheadStyle = msoArrowheadDiamond
        '.Selection.Forward = 0.5
        '.Backward = 0.5
    End With

    Selection.Type = xlPolynomial
    Selection.Forward = 0.5
    Selection.Backward = 0.5

that was built from recording the action of macro recorder, each one will need to be established as to which line it relates to so a good few lines of code